Big talk design mode the first chapter---calculator simple Factory mode PHP implementation

1<?PHP2 Abstract classOperation {3     Private $_numbera= 0;4     Private $_numberb= 0;5 6      Public function__get ($number) {7         if(isset($this-$number)) {8             return $this-$number;9}Else {Ten             Echo"The number name is ' _numbera ' and ' _numberb '"; One             Exit(); A         } -     } -  the      Public function__set ($number,$value) { -         if(isset($this-$number)) { -             $this-$number= (float)$value; -}Else { +             Echo"The number name is ' _numbera ' and ' _numberb '"; -             Exit(); +         } A     } at  -     Abstract functionGet_result (); - } -  -  - classOperation_addextendsOperation { in      Public functionGet_result () { -         $result= 0; to         $result=$this->_numbera +$this-_numberb; +         return $result; -     } the } *  $ classOperation_subextendsOperation {Panax Notoginseng      Public functionGet_result () { -         $result= 0; the         $result=$this->_numvera-$this-_numverb; +         return $result; A     } the } +  - classOperation_mulextendsOperation { $      Public functionGet_result () { $         $result= 0; -         $result=$this->_numbera *$this-_numberb; -         return $result; the     } - }Wuyi  the classOperation_divextendsOperation { -      Public functionGet_result () { Wu         $result= 0; -         if($this->_numberb = = 0) { About             Throw New Exception(' ACI yukata 暟 Juan Trajectory divisions Juan? ')); $         } -         $result=$this->_numbera/$this-_numberb; -         return $result; -     } A } +  the  - classOperationfactory { $      Public Static functionCreate_operate ($operate) { the         $oper=NULL; the         Switch($operate) { the          Case' + ': the             $oper=NewOperation_add (); -              Break; in          Case‘-‘: the             $oper=Newoperation_sub (); the              Break; About          Case‘*‘: the             $oper=NewOperation_mul (); the              Break; the          Case‘/‘: +             $oper=NewOperation_div (); -              Break; the         }Bayi         return $oper; the     } the } -  -  the $oper= Operationfactory::create_operate ('/')); the $oper->_numbera = 10; the $oper->_numberb = 20; the Echo $oper->get_result ();

Maintainable, reusable, scalable, flexible

Association: When a class ' knows ' another class, it can be associated (association)

Aggregation: Represents a weak ' owning ' relationship, which reflects that a object can contain a B object, but the B object is not part of a object.

Combination: is in a strong ownership relationship, embodies the strict part and the whole relationship, part and the whole life cycle.

Big talk design mode the first chapter---calculator simple Factory mode PHP implementation